Improvement in projectiles for ordnance



B. B. HOTGHKISS.

Projectile.

N'o 112,1 4 4. Patented Feb 28,1871.

N-PETERS. PNUITLUTRDGRAPHEE WASHINGTON d 3 timid [also in the act-of firing.-

B. BpHOTOHKISS, OF NEW YORK, N. Y.

Letters-Patcnt'No. 112,144, dated February 28, 1871.

IMPROVEMENT IN PROJECTILES FOR ORDNANCE.

The Schedule referred to in these Letters Patent and making part of the same.

To all whom it may concern ,1

Be'it known that I, B. B. HoTcHKrss, of the city and county of New York, in the State of New York, have invented certain new and useful. Improvements in Projectiles for Bifled Ordnance; and I do hereby declare that the following is a full and exact description thereof.

My invention relates to' the construction and ar- I rangemeut of the parts which enter the rifled grooves in the gun, and to means for properly confining such parts and for producin'ga' proper expansive'motion thereof. 4

The main body of the projectile is of cast-iron or.

other iigid material-not adapted to change its form.

This is first cast complete, after which certain parts are attached, which are composed of brass or other slightly-plastic or yielding material, of such size as to be introducedinto the gun through the muzzle with ease, because they do not tightly fit the gun, and are expanded in the act of firing so as to fit. tightly and hold the projectile centered in the bore, while they also cause it to assume the proper rifle motion.

I propose to term my projectile the expandingbutton projectile. 1

I will first proceed to describe what I consider the best means of carrying outmy invention, and will af-- tile, butbefore the projectile has been fired. The remaining figures show the changes made I in securing the packing to the bodyof the projectile, and

Figure 4 is a view of oue 'of the packing pieces as they are cast previous to being secured in the main body;

' Figure 6 is an'end view of the same; and

Figure '5 is a central longitudinal section.

Figure 7is an end view corresponding to fig. 6, but showing the inner end of the piece flattened to spread and lock it in the projectile, as will 1 be explainedhelow.

' Figure 8 is a side view of 'the same piece,- after being flattened and expanded over its whole surface by the intense force of the discharge.

Figure 9 represents the entire rear of the projec-- tile, with a section of the adjacent parts of the gun, before firing. The wind-age, or space between the projectile and the inner surfaces of the gun, is represented as somewhat greater than is usually practiced, in order'the better to exhibit the operation of the expansive action.

Figure 10 represents the same after the ignition-of the powderand the intense pressure thereby developed has flattened the several pieces of packing and causcdthem not only to' lock very tightly in the main part of the projectile, but also to extendoutward and, press against the bottom of the grooves in the gun, whileleaving a great portion of the interior. of the gun untouched. v

Figure ll'shows a slight modification, which gives a wedging efi'ect-in addition to the other peculiarities.

Similar letters of reference indicate corresponding parts in all the figures. v

'A is the body of the projectile. Its diameter corresponds with the bore of the gun from which it isto be tired, leaving only the ordinary five-one-huhdredths of an inch, or whatever other allowance is deemed expedient for the looseness oropen space, between the projectile and the inner surface of the bore hroper.

The projectile may be of any length which may be found expedient. It may be hollow, and adapted to contain explosive material, with any provision at thefront for igniting, or for penetrating iron-clads, or for any other purpose.

My invention relates entirely to the provision for v packing.

In what is generally known as the French system of construction of projectiles for rifled ordnance the main body of the projectile is made smooth and cylindrical, and a number of projections, corresponding to the several grooves in the gun, is provided on the external surface of the projectile, and are denominated buttons.?

. My invention provides analogous part-s,- corresponding in number and position-to the grooves in the gun, and approximately corresponding in size tothe depth and breadth of the several grooves. They may extend longitudinally of the grooves to agrcater orlesser extent, as may be preferred'.-

The drawings represent several modifications of the form in this respect. Each extend's inward, as indicated by B, and is firmly secured in the corresponding recesses in the body of the projectile.

The cast-iron between the buttons, marked A, should extend rearward a little beyond the extreme edge of the buttons, in order to protect the buttons when the projectiles are roughly handled, are stood up, or-are dropped heavily on a pavement orothei" hard substance. Some of the advantages of my invention may, however, be realized without this provision.

In the act of firing'the force of the pow der, acting on the rear of the projectile, tends to upset and to spread, and to expand radially the entire projectile, and while the cast-iron parts are too rigid to be materiallyaii'ectedeven by the severe force of'the' burning powder, the brass parts,.being'softer, yield to the .force; and the buttons expand so as to tightly till the groove.

Each button B audits wing B form a separate and independent brass casting. These parts are confined hy'dovetailing two ways; that is to sav, each part cannot escape rear-wise from'the projectile, by'reason of the cavity or recess in which it is fitted contractingin that direction; Neither can it escape radially from 'the projectile, by reason of the cavity or'recess contracting iu'that direction.

The construction of these portions is very' important, and must be studied with a-careful reference to the drawings. Referring to fig. 3, it will be seen that the sides of the recesses in each of the packing pieccs B B are narrower atithe extreme rear than at the front of each packing-piece. The packing-piece being made to [ill the'recess with tolerable tightness, it i'ollows that it cannot escape rear-wise from the projectile, being retained by the inclined op dovetailiog sides of the cavity in that direction. The packing is introduced readily by turning it in from the ouYside or periphery toward the centera. movement which the form of the cavity does not preveut.

Now, to prevent-its escaping radially, itis necessary to make the: recess also dovetailing in the radial direction; and it-i's also' .necessary that the packingpiece B shall widen at its inner end after it has been inserted. l adapt a peculiar means ibueii'ecting this widening. By making the under face of thejpackingpiece A c lncave or guttered, asrepresentedflt allows of being introduced in'the manner above described b forcing it radially inward fromthe'periphery toward the center on axis of the projectile, and .then, after having been thus introduced-in a narrow condition,

by'reason of its concave or eaves-troughed form, I

flatten the concave (and thus expand the inner end of the wing B). with a heavy hammer, ,eitherdirectly or throiwh the medium of a ro er set or, b Y a a p 1 d p plying toit a strongpressure'by means of a hydraulic press or otherwise. I v

This flattening of the inner end causes the material at that point to widen and to entirely-fill the rccess'there provided forit'. It follows that the" packing-piece 13 13', after being thus introduced, withits inner end narrowed, by being oonoaved, and' after being thus widened at the inner'end by flattening or, compressing so as to fill'the space, is firmly locked at that point, and is able to resist all the strainsto which it is subsequently exposed, either by the force of the powder or by the centrifugalforce, or byall the forces combined. 7

In all the forms of my projectile it will be observed that the packing-pieces do not lie close to the bottom of the recess, except at the extreme inner portions of the wings B. 1

- There is a space, m, under thepacking-piece. When the force of the powder is applied to the rear of the projectile it flattens this port-ion, thus filling up the cavity 'm by bringing the brass oi the packing-piece into intimate contact with the bottom of the recess- Thisv movement expands the button more perfectly,

but it will expand with some effect if no such'cavity I is left.

With brass, or bronze of medium hardness the en tire packing-piece B B may be made a'uniform cast ing, and may be allowed to expand directly into the grooves of the gun without injury.

The. material in all cases should be such as will mold or adapt, itself to the grooves of the gun and form a tight fit, and the several wings should be so nearly uniform that they will expand so nearly alike slid forward a little on the main body, by the discharge ot', the gun, and thus to expand th e'button B B 'radiall-y by virtue of the Wedge principle, as well as by the other changes of form referred to.

It will-be observed that the spaces provided for the packing-pieces to thus drive forward are narrow corresponding to the packing-pieces, and that they are separated by stout portions of the rigid iron body, so that each is directly supported thereby to resist wringing or turning around on the body. The immediate proximity of the support to the point where the-force is received by the packing gives a great advantage when this form is used.

It is possible to' operate with some success with my invention where the buttons are of less width than the grooves in the gun; but in such case the entire groove will not be filled by the button. It is also practicable to operate with a button of greater width than the grooves in the gun; but in such casesthe buttons should "be correspondingly formed, either at the time of their manufacture, or by subsequent chipping or filing, ,or other treatment, so as to allow the projectile to enter the gnneasily.

Having now fully described n y invention,

Wh'atl claimas new, and desire to secure by Letters Patent, is as follows- The means herein described for expanding packing to a defiuitely-fixed'limit by pieces which are and remain; firmly connected at one end to the main body, the same consisting of the buttons extending inward at or near the rear euds and sliding forward on the periphery in grooves which are? not only i'nclinedo'r wedge-like; but have square shoulders at their for- Witnesses:

WM. 0. DEY, O. O. L vmes. 

